Multiclassing also occasionally leads to the weak unfocused character, which is just as much of a problem (except in the occasional circumstances who m where I've seen players roll incredibly good stats and device to max-min because they can actually afford a bad build). And sometimes players who can't op to save their life will insist on branching out, inevitably making the game less fun for them when they can't keep up...

I honestly think that Multiclassing should be limited to Fears and subclasses. Even if their implementation is often somewhat subpar. It keeps balance in a narrower band and avoids a lot of build-based resentment. (But that I actually like strongly classed games anyway, but that's a separate issue).